/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: wwy
 * Date: 2024-11-10
 * Time: 14:54
 */
public class Test6 {
    public static void main(String[] args) {

        double sum = 0;
        int flg = 1;
        for (int i = 1; i <= 100; i++) {
            sum += 1.0/i * flg;
            flg = -flg;
        }
        System.out.println(sum);
    }
}
